"Chartreuse V.E.P. (Vieillissement Exceptionnellement Prolongé) is made using the same processes and the same secret formula as the traditional liqueur, and by extra long ageing in oak casks it reaches an exceptional quality."

So it was a sufficient condition. But perhaps she had a non-related cardiac arrest at the same time, compounded by a stroke, acute diabetes and tennis elbow. Together, these could very well have been fatal. (Except for the stroke.)